This invention relates to a height-adjusting device with pivotally interconnected supporting members for supporting the upper portion of a two-part body on the lower portion of the two-part body, more particularly to a safe height-adjusting device which cannot clamp the fingers of the user between the supporting members when adjusting the height of the upper portion.
Referring to FIG. 1, a conventional height-adjusting device includes two first supporting members (B), (only one is shown), and two second supporting members (C), (only one is shown), connected rotatably to the first supporting members (B) by a pivot shaft (A). A pivot pin (D) connects rotatably two toothed and curved positioning elements (E) to the first supporting members (B). A retaining shaft (C1) is secured to the second supporting members (C) and engaged with the selected notches (e) in the positioning elements (E) so as to interlock the first supporting members (B) and the second supporting members (C). The user can actuate a control lever (T) to drive the retaining shaft (C1) to engage within or disengage from the notches (e) in the positioning elements (E). The removal of the retaining shaft (C1) from the notches (e) in the positioning elements (E) allows for the rotation of the first supporting members (B) relative to the second supporting members (C) and the adjustment of the height of the device. Because the supporting members (B, C) look like the cutting blades of a pair of scissors, the fingers of the user may be clamped therebetween.